PHP Everywhere has a new posting this morning about Building Truly Portable Database Applications for PHP (an article by Daniel Convissor), with a mention of using the ADOdb database abstraction layer to support these ideas.

Daniel Convissor has written a great presentation on Building Truly Portable Database Applications for PHP. He's gone into a lot of detail, covering stuff like data type issues, concatenation operators, literal identifiers, handling of booleans, etc for an extensive list of databases.

The actual information is in the form of slides from a presentation instead of an article, but they are still quite useful for getting across the core ideas behind making your applications portable.